Instructions:

1. Leave whole. Dip in boiling water 30 seconds or more to break skins. Plunge in ice water to stop cooking. Drain on paper towels.
2. Preheat dehydrator following manufacturer instructions.
3. Arrange prepared food on drying trays, leaving small spaces between pieces for good air circulation.
4. Stir small pieces to ensure even drying. Rotate trays if recommended by dehydrator manufacturer.
5. Check for dryness at the end of the minimum drying time, and then more frequently as drying progresses. Estimated drying time is 12 to 20 hours. Let a sample piece cool to room temperature before testing.  Grapes are dry when they are tacky, but don't stick to each other.
6. Condition foods before storing. 
7. Because there is still moisture left in dried fruit.  Put in an air tight  container and shake well each day to redistribute the moisture for 7 days.  If condensation forms inside the container, the fruit needs more drying time.
8. Package dried foods in glass jars, food storage containers or plastic food storage bags in small amounts. Store containers in a cool, dark, dry area to maintain quality.

Dry time: 12-20 hours

Test for dryness: Raisin-like, no moist center

Source:

So Easy to Preserve, 6th edition, 2020